Android使用异步任务更新地图位置

我有一个地图视图，它确定用户在异步任务中的位置，然后在地图上的某些位置添加一些标记。我似乎无法在找到位置后更新地图。在运行onPostExecute之前，是否有任何可能的方法等待找到位置。我尝试在MainMapView类中包含位置侦听器，而不使用ASyncTask。这会更新地图，但会使地图变得非常缓慢和滞后。我假设这是因为每次发现新位置时地图都会更新。非常感谢您的帮助

import android.os.Bundle;
import android.os.AsyncTask;
import android.os.Looper;
import android.util.Log;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapController;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;


public class MainMapView extends MapActivity{

    private Location currentLocation;
    private String serviceName;
    private MapController mapController;
    private List<Overlay> mapOverlays;
    private ItemizedOverlay itemizedoverlay;
    private LocationManager locationManager;
    private HealthCarePractice[] practices;

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_map_view);

        Bundle retItem = getIntent().getExtras();
        serviceName = retItem.getString("serviceName");
        //Log.e("This One", serviceName);

        MapView mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        //mapView.setSatellite(true);
        mapController = mapView.getController(); 

        mapOverlays = mapView.getOverlays();
        Drawable drawable = this.getResources().getDrawable(R.drawable.androidmarker);
        itemizedoverlay = new ItemizedOverlay(drawable, this);

        Context context = this;

        MainMapViewTask task = new MainMapViewTask();
        task.execute(context);

    }

    public class MainMapViewTask extends AsyncTask<Context, Integer, Void>
    {
        Context localContext;

        @Override
        protected Void doInBackground(Context... params) {
            localContext = params[0];
            // Aquire a reference to the system Location Manager
            locationManager = (LocationManager) localContext.getSystemService(Context.LOCATION_SERVICE);

            // Define a listener that responds to location updates
            LocationListener locationListener = new LocationListener() {
                public void onLocationChanged(Location location) {
                    // Called when a new location is found by the network location provider.
                    if (location != null)
                    {
                        currentLocation = location;
                        locationManager.removeUpdates(this);
                        locationManager = null;
                        Geocoder geocoder = new Geocoder(MainMapView.this, Locale.getDefault());  

                        List<Address> list;

                        if(currentLocation == null)
                        {
                            Log.e("Message", "Location not found");
                        }else{
                            try {
                                list = geocoder.getFromLocation(
                                currentLocation.getLatitude(), currentLocation.getLongitude(), 1);
                                if (list != null && list.size() > 0) {
                                    android.location.Address address = list.get(0);
                                    //Log.e("Post Code", address.getPostalCode());
                                    String poCode = address.getPostalCode();
                                    if (poCode != null)
                                    {
                                        //Log.e("Post Code", address.getPostalCode());
                                        String searchString = buildSearchString(serviceName, poCode.replaceAll(" ", ""));
                                        //Log.e("posplit", poCode.split(" ")[0]);
                                        Log.e("Search String", searchString);
                                        RemoteData remoteData = new RemoteData("Location", searchString);
                                        practices = remoteData.getPractices();
                                    }
                                }
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                    }

                }

                public void onStatusChanged(String provider, int status, Bundle extras) {}

                public void onProviderEnabled(String provider) {}

                public void onProviderDisabled(String provider) {}
              };

            Looper.myLooper();
            Looper.prepare();
            locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            if(currentLocation != null)
            {
                GeoPoint currentPoint = new GeoPoint((int)(currentLocation.getLatitude()*1000000), (int)(currentLocation.getLongitude()*1000000));
                mapController.setCenter(currentPoint);
                mapController.setZoom(15);
                for(int i=0; i< practices.length; i++)
                {
                    int latitude = (int)(practices[i].getLatitude()*1000000);
                    int longitude = (int)(practices[i].getLongitude()*1000000);
                    currentPoint = new GeoPoint(latitude, longitude);
                    mapController.setCenter(currentPoint);
                    mapController.setZoom(15);
                    String[] addressLines = practices[i].getAddress().getAddressLines();
                    StringBuilder sb = new StringBuilder();
                    for(int y=0; y<addressLines.length; y++)
                    {
                        sb.append(addressLines[y]);
                        sb.append('\n');
                    }
                    sb.append(practices[i].getAddress().getPostcode());
                    sb.append('\n');
                    sb.append("Telephone: ");
                    sb.append(practices[i].getTelephone());
                    OverlayItem currentOverlayItem = new OverlayItem(currentPoint,practices[i].getTitle(),sb.toString());
                    itemizedoverlay.addOverlay(currentOverlayItem);
                    mapOverlays.add(itemizedoverlay);
                }
            }
        }

    }
}

导入android.os.Bundle；
导入android.os.AsyncTask；
导入android.os.Looper；
导入android.util.Log；
导入com.google.android.maps.MapActivity；
导入com.google.android.maps.MapView；
导入java.io.IOException；
导入java.util.List；
导入java.util.Locale；
导入android.content.Context；
导入android.graphics.drawable.drawable；
导入android.location.Address；
导入android.location.Geocoder；
导入android.location.location；
导入android.location.LocationListener；
导入android.location.LocationManager；
导入com.google.android.maps.GeoPoint；
导入com.google.android.maps.MapController；
导入com.google.android.maps.Overlay；
导入com.google.android.maps.OverlayItem；
公共类MainMapView扩展了MapActivity{
私人位置；
私有字符串serviceName；
专用地图控制器；
私有列表覆盖图；
私人项目化Overlay项目化Overlay；
私人场所经理场所经理；
私人医疗机构[]机构；
@凌驾
受保护的布尔值isRouteDisplayed（）{
返回false；
}
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（右布局主地图视图）；
Bundle retItem=getIntent（）.getExtras（）；
serviceName=retItem.getString（“serviceName”）；
//Log.e（“这一个”，serviceName）；
MapView MapView=（MapView）findViewById（R.id.MapView）；
mapView.SetBuilTinZoomControl（真）；
//mapView.setSatellite（真）；
mapController=mapView.getController（）；
mapOverlays=mapView.getOverlays（）；
Drawable Drawable=this.getResources（）.getDrawable（R.Drawable.androidmarker）；
itemizedoverlay=新itemizedoverlay（可绘制，此）；
上下文=这个；
MainMapViewTask任务=新建MainMapViewTask（）；
执行（上下文）；
}
公共类MainMapViewTask扩展了AsyncTask
{
语境局部语境；
@凌驾
受保护的Void doInBackground（上下文…参数）{
localContext=params[0]；
//获取对系统位置管理器的引用
locationManager=（locationManager）localContext.getSystemService（Context.LOCATION\u服务）；
//定义响应位置更新的侦听器
LocationListener LocationListener=新LocationListener（）{
已更改位置上的公共无效（位置）{
//当网络位置提供程序找到新位置时调用。
如果（位置！=null）
{
当前位置=位置；
locationManager.RemoveUpdate（此）；
locationManager=null；
Geocoder Geocoder=新的地理编码器（MainMapView.this，Locale.getDefault（））；
名单；
如果（currentLocation==null）
{
Log.e（“消息”，“未找到位置”）；
}否则{
试一试{
list=geocoder.getFromLocation(
currentLocation.getLatitude（），currentLocation.getLatitude（），1）；
if（list！=null&&list.size（）>0）{
android.location.Address=list.get（0）；
//Log.e（“邮政编码”，地址.getPostalCode（））；
字符串poCode=address.getPostalCode（）；
if（poCode！=null）
{
//Log.e（“邮政编码”，地址.getPostalCode（））；
String searchString=buildSearchString（serviceName，poCode.replaceAll（“，”）；
//Log.e（“posplit”，poCode.split（“”[0]）；
Log.e（“搜索字符串”，searchString）；
RemoteData RemoteData=新的RemoteData（“位置”，搜索字符串）；
practices=remoteData.getPractices（）；
}
}
}捕获（IOE异常）{
e、 printStackTrace（）；
}
}
}
}
public void onStatusChanged（字符串提供程序、int状态、Bundle extra）{}
公共无效onProviderEnabled（字符串提供程序）{}
公共无效onProviderDisabled（字符串提供程序）{}
};
Looper.myLooper（）；
Looper.prepare（）；
locationManager.RequestLocationUpdate（locationManager.NETWORK\u提供程序，0，0，locationListener）；
返回null；
}
@凌驾
受保护的void onPostExecute（void结果）{
if（currentLocation！=null）
{
地理点currentPoint=新的地理点（（int）（currentLocation.getLatitude（）*1000000），（int）（currentLocation.getLatitude（）*1000000））；
mapController.setCenter（当前点）；
mapController.set
import android.os.Bundle;
import android.os.AsyncTask;
import android.os.Looper;
import android.util.Log;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;

import java.io.IOException;
import java.util.List;
import java.util.Locale;


import android.content.Context;
import android.graphics.drawable.Drawable;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapController;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;


public class MainMapView extends MapActivity{

    private Location currentLocation;
    private String serviceName;
    private MapController mapController;
    private List<Overlay> mapOverlays;
    private ItemizedOverlay itemizedoverlay;
    private LocationManager locationManager;
    private HealthCarePractice[] practices;
    private boolean mapDrawn = false;

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_map_view);

        Bundle retItem = getIntent().getExtras();
        serviceName = retItem.getString("serviceName");
        //Log.e("This One", serviceName);

        MapView mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        //mapView.setSatellite(true);
        mapController = mapView.getController(); 

        mapOverlays = mapView.getOverlays();
        Drawable drawable = this.getResources().getDrawable(R.drawable.androidmarker);
        itemizedoverlay = new ItemizedOverlay(drawable, this);

        Context context = this;

        /*
        MainMapViewTask task = new MainMapViewTask();
        task.execute(context);
        */

        locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

        // Define a listener that responds to location updates
        LocationListener locationListener = new LocationListener() {
            public void onLocationChanged(Location location) {
                // Called when a new location is found by the network location provider.
                if (location != null)
                {
                    currentLocation = location;
                    locationManager.removeUpdates(this);
                    locationManager = null;
                    Geocoder geocoder = new Geocoder(MainMapView.this, Locale.getDefault());  

                    List<Address> list;

                    if(currentLocation == null)
                    {
                        Log.e("Message", "Location not found");
                    }else{
                        try {
                            list = geocoder.getFromLocation(
                            currentLocation.getLatitude(), currentLocation.getLongitude(), 1);
                            if (list != null && list.size() > 0) {
                                android.location.Address address = list.get(0);
                                //Log.e("Post Code", address.getPostalCode());
                                String poCode = address.getPostalCode();
                                if (poCode != null)
                                {
                                    //Log.e("Post Code", address.getPostalCode());
                                    String searchString = buildSearchString(serviceName, poCode.replaceAll(" ", ""));
                                    //Log.e("posplit", poCode.split(" ")[0]);
                                    Log.e("Search String", searchString);
                                    RemoteData remoteData = new RemoteData("Location", searchString);
                                    practices = remoteData.getPractices();
                                    if(!mapDrawn)
                                    {
                                        mapDrawn = true;
                                        if(currentLocation != null)
                                        {
                                            GeoPoint currentPoint = new GeoPoint((int)(currentLocation.getLatitude()*1000000), (int)(currentLocation.getLongitude()*1000000));
                                            mapController.setCenter(currentPoint);
                                            mapController.setZoom(15);
                                            for(int i=0; i< practices.length; i++)
                                            {
                                                int latitude = (int)(practices[i].getLatitude()*1000000);
                                                int longitude = (int)(practices[i].getLongitude()*1000000);
                                                currentPoint = new GeoPoint(latitude, longitude);
                                                mapController.setCenter(currentPoint);
                                                mapController.setZoom(15);
                                                String[] addressLines = practices[i].getAddress().getAddressLines();
                                                StringBuilder sb = new StringBuilder();
                                                for(int y=0; y<addressLines.length; y++)
                                                {
                                                    sb.append(addressLines[y]);
                                                    sb.append('\n');
                                                }
                                                sb.append(practices[i].getAddress().getPostcode());
                                                sb.append('\n');
                                                sb.append("Telephone: ");
                                                sb.append(practices[i].getTelephone());
                                                OverlayItem currentOverlayItem = new OverlayItem(currentPoint,practices[i].getTitle(),sb.toString());
                                                itemizedoverlay.addOverlay(currentOverlayItem);
                                                mapOverlays.add(itemizedoverlay);
                                            }
                                        }
                                    }
                                }
                            }
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }

            }

            public void onStatusChanged(String provider, int status, Bundle extras) {}

            public void onProviderEnabled(String provider) {}

            public void onProviderDisabled(String provider) {}
          };

        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);

    }

@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow)
{
    if(!shadow)
    {
        super.draw(canvas, mapView, false);
    }
}